Quantum estimation via the minimum Kullback entropy principle
- Dipartimento di Fisica dell'Universita di Milano, I-20133 (Italy) and Dipartimento di Matematica e Fisica dell'Universita dell'Insubria, I-22100, Como (Italy)
We address quantum estimation in situations where one has at disposal data from the measurement of an incomplete set of observables and some a priori information on the state itself. By expressing the a priori information in terms of a bias toward a given state, the problem may be faced by minimizing the quantum relative entropy (Kullback entropy) with the constraint of reproducing the data. We exploit the resulting minimum Kullback entropy principle for the estimation of a quantum state from the measurement of a single observable, either from the sole mean value or from the complete probability distribution, and apply it as a tool for the estimation of weak Hamiltonian processes. Qubit and harmonic oscillator systems are analyzed in some detail.
- OSTI ID:
- 21020662
- Journal Information:
- Physical Review. A, Vol. 76, Issue 4; Other Information: DOI: 10.1103/PhysRevA.76.042120; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1050-2947
- Country of Publication:
- United States
- Language:
- English
Similar Records
Redundant imprinting of information in nonideal environments: Objective reality via a noisy channel
On variational definition of quantum entropy